Lymphatic Mapping for Melanoma: Long-term Results of Regional Nodal Sampling With Radioguided Surgery

Imaging in cutaneous melanoma

Cutaneous melanoma (CM) is a common malignancy and imaging, particularly lymphoscintigraphy (LS), positron-emission tomography with 2-fluoro-2-deoxyglucose (FDG-PET), ultrasound, radiography computed tomography (CT) and magnetic resonance imaging have important roles in staging and restaging, surgical guidance, surveillance and assessment of recurrent disease. This review aims to summarize the available data regarding these and other imaging modalities in CM and provide the basis for subsequent formulation of guidelines regarding the use of imaging in CM. PubMed and Medline searches were performed and reference lists from publications were also searched. The published data were reviewed and tabulated. There is level I evidence supporting the use of LS and sentinel lymph node biopsy in nodal staging for CM. There is level III evidence demonstrating the superiority of ultrasound to palpation in the assessment of lymph nodes in CM. There is level IV evidence supporting FDG-PET in American Joint Committee on Cancer stage III/IV and recurrent CM and that FDG-PET/CT may be superior to FDG-PET. Level IV evidence also supports the use of CT in the same group of patients and the role of CT appears to be complementary to FDG-PET. Various imaging modalities, especially LS/sentinel lymph node biopsy and FDG-PET/CT, add incremental information in the management of CM and the various modalities have complementary roles depending on the clinical situation.

Sentinel lymph node biopsy in patients with Stage I/II melanoma: Clinical experience and literature review

BACKGROUND

The sentinel lymph node (sN) represents one of the most powerful predictors of the outcome of patients with Stages I and II cutaneous melanoma, and may be relevant for the therapeutic planning of early-stage melanoma patients. Since adopting the technique of lymphatic mapping with vital blue dye (Patent Blue-V) in July 1993, we have periodically up-dated the methodology and revised our results in order to define the contribution of radio-guided surgery (RGS) to the detection of the sN as well as the role of intraoperative frozen section examination of the sN.

MATERIALS AND METHODS

Between July 1993 and December 1997, 180 patients with clinically node-negative primary cutaneous melanoma (Stages I-II) underwent sN biopsy followed by "selective lymph node dissection" (SLND) whenever sN metastasis was detected. Presently, complete data are available in 165 patients who were divided into two consecutive subsets of 39 and 126 patients, based on the technique for the identification of the sN: Patent Blue-V only or Patent Blue-V associated to RGS. Moreover, in this second subset of patients intraoperative frozen section findings were compared with definitive pathologic examination.

RESULTS

As regards the first subset of 39 patients (17 males and 22 females; mean age 51.3 years), the sN was identified in 35 patients (89.7%); 8 patients (22.8%) were found to have metastatic melanoma cells in their sN, and they all underwent SLND of the affected basin. As regards the second set of 126 patients (54 males and 72 females; mean age 53.5 years), the sN was detected in every case by means of the combined technique (Patent Blue-V and RGS): in 4 of 126 patients (3.2%), the sN was detected by means of RGS only whereas in no patient was the sN detected by Patent Blue-V only. Frozen section examination was performed in 123 of 126 patients who had sN detection by Patent Blue-V and RGS, and the intraoperative examination had a sensitivity of 66.6% (22 of 33), specificity of 100% (90 of 90), negative predictive value of 89.1% (90 of 101), and accuracy of 91% (112 of 123). The benefit of frozen section examination in avoiding a two-stage procedure was 17.9% (22 of 123 patients). In patients with thicker lesions (pT(3)-pT(4)), the sensitivity and the benefit of intraoperative examination were 76% (19 of 25) and 32% (19 of 59 patients), respectively.

CONCLUSIONS

Sentinel node lymphadenectomy can be better accomplished when both procedures (lymphatic mapping with Patent Blue-V and RGS) are used because the two methods look quite complementary. In fact, the use of the radiocolloid mapping allows to detect a hot spot in the regional basin prior to making the skin incision in order to perform a minimal invasive access, and it may also more accurately differentiate the true sN from a secondary echelon node (non-sN). The use of frozen section examination should be restricted to patients with pT(3)-pT(4) primary melanoma, due to the higher sensitivity and benefit in terms of avoiding a two-stage operative procedure.

Nodal staging in localized melanoma. The experience of the Brescia Melanoma Unit

BACKGROUND AND OBJECTIVES

We report our experience with patients affected by cutaneous melanoma undergoing sentinel node (SN) biopsy.

METHODS

From November 1997 to October 2000 we performed 128 selective lymphadenectomies (SN biopsy) on 127 patients with cutaneous melanoma with Breslow thickness>1 mm or regression or ulceration. Age, sex, tumour location ad histology were recorded.

RESULTS

Two hundred and thirty eight SNs were identified by lymphoscintigraphy in 167 lymphatic stations, 236 of them were identified intraoperatively using a gamma probe and patent blue V injection. Twenty-one patients had SNs with melanoma metastases (15.8%), 12 patients in the groin, eight patients in the axilla and one patient in the neck. After therapeutic lymphadenectomy eight more lymph nodes with metastases of melanoma were found in the specimens of three patients. After a follow-up ranging from 10 to 56 months the results are that 111 patients are free of disease. Ten patients died. Three patients have visceral metastases and are alive. One patient has developed two more melanomas. One patient was lost to follow-up.

CONCLUSIONS

Our data confirm the clinical reliability of the SN technique in melanoma; for optimisation of the therapeutic strategy, this technique might be considered the standard method of nodal staging in the evaluation of melanoma patients.

[Lympho-gammagraphy and study of sentinel node in cutaneous melanoma]

OBJECTIVE

To evaluate the role of selective sentinel lymph node dissection to reduce the number of unnecessary lymphadenectomies in patients with intermediate risk of melanoma and without clinical evidence of regional node and distant metastases.

MATERIAL AND METHOD

We studied 65 patients with stage I and II melanoma. Only vital blue dye mapping was carried out in nine patients and combined lymphatic mapping with both blue dye and lymphoscintigraphy was used in the remaining 56 patients.

RESULTS

The sentinel node was identified in 63 of 65 patients (97%). Only eighth patients (12%) were found to have metastatic melanoma cells in their sentinel node.

CONCLUSIONS

Our findings confirm that the intraoperative lymphatic mapping of the sentinel node using both blue dye and radiodetection is an appropriate and simple technique for selecting patients who are more likely to benefit from lymph node dissection.

Surgical Management of Malignant Melanoma Using Dynamic Lymphoscintigraphy and Gamma Probe-Guided Sentinel Lymph Node Biopsy: The Emory Experience

Sentinel lymph node (SLN) biopsy is revolutionizing the surgical management of primary malignant melanoma. It allows accurate nodal staging which targets patients who may benefit from regional lymphadenectomy and systemic therapy. This is a retrospective review of patients treated at Emory University for stage I and II malignant melanoma with gamma probe-guided SLN biopsy from 1/1/94 to 6/30/98. Three hundred sixty patients (males 228, females 132) were identified. Primary melanoma sites included: head and neck 58, trunk 148, and extremities 154 (upper 71, lower 83). Primary tumor staging was T1 9, T2 134, T3 153, and T4 64. SLNs were successfully identified in 99.7 per cent of patients and 98.9 per cent of nodal basins mapped. In 275 (76.6%) cases a single draining nodal basin was identified. In 84 (23.3%) cases there were multiple draining nodal basins. Positive SLNs were identified in 63 patients (17.5%). SLN positivity by tumor staging was T1 0 per cent, T2 9.0 per cent, T3 22.2 per cent, and T4 26.6 per cent. The overall recurrence rate was 11.9 per cent. Recurrences by SLN status were SLN+, 27 per cent, and SLN-, 8.8 per cent. Regional recurrence occurred in 7 (2.4%) of the 297 with negative SLN biopsies and 7 (11.1%) of the 63 with positive SLN biopsies. Dynamic lymphoscintigraphy and gamma probe-guided SLN localization was successful in more than 98 per cent of cases. Patients with negative SLN biopsies have a low risk of recurrence.

Lymphatic mapping for Merkel cell carcinoma

Merkel cell trabecular carcinoma of the skin has a prognosis poorer than expected for a small skin lesion. An early diagnosis and prompt treatment can contribute to improve survival in cases of this aggressive skin tumor. A wide local excision is indicated for localized disease. Elective lymph node dissection is controversial. The authors report a rare case of Merkel cell tumor treated with wide local excision and sentinel lymph node biopsy.

Sentinel node localization in primary melanoma: preoperative dynamic lymphoscintigraphy, intraoperative gamma probe, and vital dye guidance

BACKGROUND

Sentinel node (SN) biopsy can be used to select patients with primary melanoma for therapeutic lymphadenectomy. The aim of the study was to assess the efficacy of 3 methods to locate the SN: preoperative dynamic lymphoscintigraphy, intraoperative patent blue dye (PBD), and gamma-detecting probe (GDP).

METHODS

We studied 133 patients with cutaneous melanoma and clinically negative lymph nodes. Within 24 hours before surgery, colloid labeled with technetium 99m was injected intradermally around the site of the primary melanoma. The patients were studied before their operations by using dynamic lymphoscintigraphy. A total of 208 SNs were found in 164 lymph node basins. In addition, all the patients had PBD injected immediately before the surgical procedure. When the blue-stained node was identified intraoperatively, its radioactivity level was measured with the GDP. In the absence of blue coloration, the GDP was used to trace the SN.

RESULTS

Of 208 SNs, 168 (80.8%) were identified in the regional draining basin during intraoperative lymphatic mapping by using PBD. By using the GDP method, 202 (97.1%) of 208 were identified (GDP vs PBD; P < .01). By combining the 2 methods, 206 (99%) of 208 SNs were detected. Of the 133 patients, 29 (21.8%) had pathologically positive SNs, and were subsequently subjected to regional lymphadenectomy. In 26 (89.7%) of 29 patients, the SN was the only node with metastasis. Three cases (10.3%) of recurrence in patients with microscopic SN metastasis and 7 cases (6.7%) of recurrence in patients without SN metastasis were found during a median follow-up of 566 days.

CONCLUSIONS

Preoperative dynamic lymphoscintigraphy and intraoperative mapping with PBD and GDP offer simple and reliable methods of staging regional lymph nodes without subjecting every patient to a regional lymphadenectomy.

Recent advances in melanoma staging and therapy

BACKGROUND

Recent advances in the staging and treatment of melanoma were reviewed.

METHODS

A literature-based review was performed.

RESULTS

The current American Joint Committee on Cancer (AJCC) Staging system for melanoma has several drawbacks. Proposed changes in the staging system to take into account simplified tumor thickness categories, tumor ulceration, and the number (rather than size) of nodal metastases will allow stage groups with more uniform prognosis. The widespread application of sentinel lymph node biopsy for nodal staging allows accurate nodal staging with minimal morbidity. Reverse transcriptase-polymerase chain reaction (RT-PCR) is a very sensitive molecular staging test that may prove useful for identifying early metastatic disease. There is finally an effective adjuvant therapy for melanoma--interferon alfa-2b. Other adjuvant therapies, including melanoma vaccines, may provide effective and less toxic alternatives. New immunotherapy and gene therapy strategies are under investigation.

CONCLUSIONS

Ongoing and future adjuvant therapy trials will benefit from improved melanoma staging by accrual of homogeneous groups of patients. New approaches for adjuvant therapy await completion of clinical trials. Innovative new therapies offer hope for patients with advanced disease.

[Managing cutaneous melanoma]

Cutaneous melanoma represents the main cause of death among skin cancers. Early diagnosis gives, for the time being, the only possibility for high rate of curative treatment. Diagnosis is based on pathological findings, and at primary tumor stage. Breslow thickness of the lesion is the best prognostic index. At local stage of the disease, treatment is precisely codified by international recommendations and consensus conferences. Follow-up after surgical treatment is also well codified. Treatment of lymph node invasion or metastatic disease is, on the other hand, less codified. Despite recent advances, especially in immunotherapy, treatment of advanced stages of melanoma remains difficult.

Sentinel lymph node biopsy using lymphoscintigraphy

Cancer surgery has existed as an elective treatment modality for more than 150 years, yet it is relatively unsophisticated in light of the advances seen in other medical disciplines. Using the nuclear medicine technique of lymphoscintigraphy (i.e., mapping lymph nodes using a radioactive isotope), the surgeon can perform a sentinel lymph node biopsy that targets only the lymph nodes that first drain a primary tumor site. This procedure can provide accurate staging information without risking the potential morbidity associated with lymph node dissection. This type of precise biopsy is made possible by using a gamma-detecting instrument coupled with an ultrasensitive probe designed for intraoperative use.